Alternating-current electromagnet



Aug. 31 1926.

f E. E. TAEUBERT ALTERNATING CURRENT ELECTROMAGNET Filed March 0 1920 IN V EN TOR. l a murzd l. ]&ezz6eri L ATTORNE S.

Patented Aug. 31, 1926.

UNITED STATES PATENT OFFICE. i

EDMUND E. TAEUBERT, OF-LOS ANGELES, CALIFORNIA, ASSIGNOR T0 LEO M. HARVEY, or os ANGELES, CALIFORNIA.

ALTERNATING-CURRENT ELECTROMAGN ET.

Application filed March so, 1926. Serial no. 372,376.

My invention relates to electro-magnets adapted for use in connection with alternating currents and the mainobject thereof is to provide a magnet with a nearlyuniform pull throughout'its rated range of action, together with certain structural features and characteristics for supporting the part of the magnet made necessary by the radical departure from' the ordinary and well known type of such magnets.

It is a Well known fact that the maximum pull of an electro-magnet is attained at the moment the armature engages the core of the magnet and the amount of pull is de creased as the gap between thearmature and the magnet core is increased. This being the case the use of such magnets for many purposes is entirely unsatisfactory and impracticable. It is an object, therefore, of

my invention to overcome the aforementioned difficulties and objections by the provision of a magnet in which the ull is as nearly uniform as possible from t e moment of energization to the limit of action of the armature.

The magnet forming the subject matter of this invention, therefore, is not one which imparts an intense pull at thefinal closing moment only but one which imparts a nearly uniform pull around a central shaft through an arc, or range of action of approximately 7 5 degrees and permits of a continuous pulling momentfrom one extreme of the arc to the other. At the end of the arc the magnet assumes a closed iron circuit such as is desirable for practical purposes and it j requires but a minimum of power to hold it in such position.

An object also is to provide a magnet of a character which will insure economy of operation and the use of a limited quantity of power for an unlimited time in the event of an inrush of current.

A further object is to provide a magnet capable of being used in any position Without overheating and subject to no harm or injury due to continuous impulses, as in other types of ma ets.

a A still further 0 ject is to provide a sub stantial structure for'maintaining the magnet pjirts in proper operative position and ca a le of detac ment for any purpose, at wi 1. Other objects will appea 21s the de scription of my invention progresses.

In order to carry out the above and other objects of this invention I have provided a laminated keeper held between like mountlugs and arranged concentrically about a centered shaft on which the armature is mounted. Said'kceper has opposed spirally formed pole faces diverging in opposite directions from an imaginary concentric circle about the axis of the armature shaft, with air gaps in the keeper midway of said pole faces. The armature has corresponding faces likewise formed and arranged so that when rotated in the direction of the keeper pole faces the nearest points on the armature faces will be at a maximum distance from the adjacent end of said keeper faces. The

further advance of the armature decreases the distance proportionately between succes sive points on the keeper and armature mo- -mentarily opposite each other during the of the drawing for, indicating the same and like parts. In said drawings:

Fig. 1 is an exterior side elevation of my improved magnet.

Fig. 2 is a typical end elevation of the same. Fig. 3 is a sectional plan thereof. Fig. 4 is a diagrammatic sectional elevation of the magnet in closed position.

Fig. 5 is a similar view with the magnet partially closed.

' F ig. 6 is a similar view With the magnet completely open.

As shown in said drawings the magnet of my invention conprises in the main a keeper composed of spaced portions K and 'K and formed of a plurality of thin laminations 1, 1, etc., air gaps a, a, being provided between the keeper portionsrend supports E and E" of continuous character having feet F, F, etc., for supporting the magnet upon a flat surface; a plurality of stay bolts B, B, etc., for holding the said parts together for use; and an armature A concentrically mounted internally of the keeper portions on a shaft S.

End portions E and E may have suitable vents 2, 2, etc., therein and the stay bolts B extend through suitable lugs 3, etc, and through corresponding extensions a, on the keeper portion K, and K. In this connection it will be noted that two of the bolts B should be of brass or other suitable nonmagnetic material so as to preclude the establishment of what is known as a magnet circuit in the keeper.

Bosses 5, and 5 are provided, respectively, on the end portions E and E, in which the shaft S is journaled and may be extended substantially therefrom at one or both ends so as to provide means of attachment for an operating member of any character, as at 0.

Considering the keeper port-ions K and K as a unit for the purpose of description, said keeper has four separate portions, formed in pairs, of like character and contour. The opposite pole faces (3 and 6 thereof, the continuity of which is broken only by the air gaps a, a, which, as stated are substantially midway of the extremities of said portions, are diametrically opposed across the axis of the shaft S and diverge equally from an imaginary line concentric with the axis of said shaft, but in opposite directions. Likewise the curved portions 7 and T of said keepers are diametrically opposite each other and are also equally divergent from an imaginary concentric circle of larger diameter than the first mentioned circle.

A pair of the bolts B extend through apertures 8 in the extensions 9 of the portions 7 and 7, while the other pa r of bolts are positioned between the extensions a formed on and midway of the extremities of the portions 6 and G centrally of the air gaps a and (4. Nuts 10, 10, etc., on the ends of said bolts hold the ends E and E and the keeper together.

The armature a; is also composed of a plurality of lam nations 11, 11, etc., held together by means of rivets, 12, 12 and said armature is held fixed on the shaft S by means of a key '13. The enlarged portions ll and 1-1 of the armature have faces 15 and 15, respectively, which correspond to the faces 16 and 16 on the interior of the keeper K and K and are about of equal extent as compared thereto. The central portion of the armature is reduced so as to provide space for the energizing winding 1V which surrounds the central portion of the armature.

It will be noted by reference to Figs. 4, 5 and 6, that the faces 15 and 15 on the armature A and those 16 and 16 on the keeper K-K are substantially concentric in all positions, the minimum space therebetween being provided, as shown in Fig. 4, when the magnet is closed, and the maximum space being provided, as shown in Fig. 6, when the magnet is open. The direction of rotation, as indicated in Figs. 5 and 6 is clockwise.

In operation, the moment that the magnet is energized the points 17 on the armature attract the points 18 on the keeper and cause the movement of the armature in a clockwise direction, successive points on the keeper being likewise attracted by successive points on the armature until the final closed position shown in Fig. 4 is attained. In this closed position the points 1'7 on the armature will be substantially opposite the points 18 on the keeper while the points 17 on said armature will likewise be opposite the points 1.8 on the keeper. In open position the armature assumes the normal position indicated in Fig. (3, opposite the portions 7 and 7 of the keeper.

As compared with other types of magnets it will be noted that I have provided a magnet in which the armature is wound and constitutes the attractor while the keeper is the attracted clementjust the reverse of the usual magnets. Also the wound armature is rotatably held and operates entirely within the conlines of the keeper. Furthermore the keeper is a split keeper as compared with the usual form of continuous iron keeper and prevents the establishment of what is known as a magnetic circuit between the ends of the keeper yokes. The advantages of this form of construction will be readily apparent to those skilled in the art and a very satisfactory design is permitted by the absence of unsightly parts, while the delicate parts and all of the wires of the magnet are enclosed and while easily accessible for any purpose they are not subject to breakage or displacement due to rough handling and con tact with other elements.

My magnet comprises the magnetic characteristics of an iron clad bi-polar motor frame and imparts to its armature a continuous axial torque through afractional turn by means of the attraction between polar surfaces, and not by means of any induced secondary currents.

The wound movable armature of my de vice which is concentrically mounted between the two keeper yokes K and. K which are separated, as described, by air gaps a and a formed midway of the spiral pole faces constitute definite pole axes in the mass of iron surrounding the armature and increase the air gap in the magnetic circuit at the beginning of the turning moment, and the air gaps formed between the adjacent faces of the armature and keeper are constantly diminished as the armature advances.

What I claim, is:

1. An alternating current magnet comprising concentrically mounted split keeper yokes, and a bipolar armature mounted centrally relative thereto.

2. An alternating current magnet comprising stationary keeper elements having opposed pole faces diverging from a true are described about a common axis, an armature rotatably mounted for operation about said common axis and having opposed pole faces correspondingly divergent, and a winding on said armature whereby when energized, said armature will be rotated by reason ofthe attraction between the keeper and armature pole faces.

3. An alternating current magnet comprising keeper elements having bi-polar faces diverging in opposite directions from true arcs having a common center and an armature rotatably held between said keeper elements having an axis common to the center of said arcs and having bi-polar faces correspondinlgly formed, and a winding on said armature whereby one of said elementsor said armature may be moved by reason of the attraction between said polar faces when said magnet is energized.

4. An alternating current magnet comprising relatively movable elements having correspondingly formed spiral pole faces in diametrically opposed relation and extending throughout the arc of movement of said movable elements, one set of said pole faces constituting the attractors and the other set the attracted surfaces.

5. An alternating current magnet comprising keeper elements, a wound movable armature mounted therewithin, said keepers and said armature having pole faces forming opposite spirals, said armature also having correspondingly formed spiral pole faces and adapted when the magnet is energized to be moved by the attraction between the pole faces as the same are continually moved together.

6. An alternating current magnet comprising spaced stationary keeper elements having internal spiral pole faces, a wound armature centrally mounted therebetween and having spiral pole faces, whereby when the magnet is energizedthe attraction between the pole faces will impart a continuous rotary motion to said armature throughout its arc of action.

7. An alternating current magnet comprising oppositely mounted keeper elements having air gaps therebetween, an armature rotatably mounted centrally between said keeper elements, spiral pole faces of like extent on said keeper elements bisected by said air gaps, and corresponding spiral pole faces on said armature, for imparting rotative motion to said armature when the magnet is energized, by reason of the attraction of said pole faces throughout a continuous arc of action.

8. An alternating current magnet comprising opposite keeper elements having spiral pole faces, a wound bi-polar armature mounted centrally within said keeper elements and having spiral pole faces, a shaft for said armature, said armature, when energized, serving to impart a continuous axial torque throughout a fraction of a turn to said shaft, and the armature and keeper elements forming at the completion of the turning moment a closed iron magnetic circuit.

9. An alternating current magnet comprising stationary keeper elements having air gaps therebetween, supporting members therefor, a shaft centrally journaled in said supporting members, an armature. fixed to said shaft between said keeper elements, a coil on said shaft for connection with a source of current, opposed spiral pole faces being provided on said keeper elements and like faces on said armature, whereby the en ergization of said coil will effect the rotation of said armature by reason of the attraction between the said pole faces.

10. A magnet for alternatin g currents comprising a pair of keeper elements having air gaps therebetween, and a wound bi-polar armature mounted for rotation therebetween, said elements having spirally disposed pole faces continuing thru the full arc of normal movement of the armature, and said armature having corresponding spiral faces, whereby the distance between the keeper faces and the armature faces decreases with the advance movement of said armature.

EDMUND E. TAEUBERT. 

